In a typical layout, the drive shaft for the pump--which may be the nose of the engine crankshaft--has a central splined or slotted bore to receive the splined or tang end or the driven shaft in the pump. This driven shaft projects through a pump body face, and that face mates with the engine block/sump and alignment is achieved by a circular formation or step machined in said face and a complementary step formation on the pump body. Radially outwardly of the step the face is apertured for securing bolts.